Fuel pump for internal-combustion engines



Dec. 14 1926. Y 1,610,997

D. l.. H. CAFFERATA FUEL PUMPIOR INTERNAL COMBUSTION ENGINES Filed March 20, 1924 :f'l/ y] may s s Patented D.14,192e.

PATENTor-'Flca Domandor LUIS nannnrxus cuentan, or Bonneval, NnrHEnLAz-ans.

` FUEL Pour ron INTERNAL-consolation intensas. y

appueaaon filed umh a0, 1m, semi no. 700,8, and 1n Netherluias nay 11, 192s.

The present invention relates to improvements in a fuel pumpvfor internal c ombustion engines, in which the diiferencem pressure in the compression space acts on a dif- 5 ferential piston, whichA is connected to the plunger of the ump. I am aware, t at a fuel-pump has already been designed, whereby the movement of the plunger results o f the difference in pressure.

1n the com ression s ace. This pressure is transmitte to a di erential is connected to the plunger, w ilst the pressure valve is a spring controlled needle valve. This pump however needs a mechanical drive.

The pump according to the invention works quite automatically and needs no cams nor eccentrics and can be readily attached to an cylinder by means of a projection, which is a part of thepump, containing the fuel-delivery channel.

For this reason, the invention is particularly suitable to be applied when reconstructing a Steamship into a motorshlp and re-employing a art of the existing plant,

such as the cran shaft.

The invention is illustrated in the accompanying drawings in which- Fig. l is a section lengthwise, Fig. 2 a section of a part of the pump according to another form of construction, and

Fig. 3 a section of another form of construction of the pump.

The fuel pump is provided with a threaded or flanged projection l, with which it can be screwed or attached on a cylinder-head and consists of a cylindrical body 2, which is bored lengthwise. In this bore, there are two plungers, one of which is the smallest' plunger of a differential piston.3, the other one being a needle-valve 7. The larger plunger of the differential piston is situated in a bore 4, which communicates with the combustion space of the cylinder by means of a channel 5. The surface of the last mentioned plunger equals about ten times that of the smallest one; thus the ressure in the compression space is increase tenfold when transmitted by the differential piston. The needle valve is provided with an adjustable spring 6 which presses the valve on its seat, said valve when being lifted by the pressure of the fuel situated between the two plungers, uncovers the channel 8 made in the projection 1 and leading to the spraying nozzle. The fuel-feeding device comiston, which prises an inlet pipe 9, a valve 10 and a nonreturn valve 11.` The differential piston and 1ts springA are cooled by a liquid lead tllxrough the ports 12. The channel 5, may a so on Fig. 3 of the drawings. This makes assembhng particularly easy and moreover diminishes the possibility of leaking. Instead ofleading the fuel in the space between the plungers 3 and 7, this can be done such as indicated in 1. The fuel-inlet is located remote from the end of the lunger 3 and this plunger is provided wit a radial and an axlal bore 13 respectively 14 (Fig. 2) whereby the latter contains a non-return valve 15. The working of my fuel pump is as follows:

The fuel entering at 9 which serves to control t admitted, and comes into the plungers asses the valve 10, e quantity of fuel the space between 3 and 7, At the compression be made in the projection 1 as shown` dash-line on Fig.

stroke, the pressure in the cylinder increases and this pressure is transmitted through thev channel 5 to the space 4, where it acts on the piston 3, and is transmitted further tenfold to the fuel situated between the plungers. The pressure of this fuel shall amount to 250-300 atm. The non-return valve 11 resp. 15 prevents the fuel from escaping through the inlet valve. The tension of the spring 6 is regulated. in such a manner, that the needle-valve is lifted at the moment the cvllnder piston has nearly reached its up r dead centre. Thus a quantity of fuelpois pressed through the channel 8 tothe spraylng nozzle and into the cylinder at a. pre-f determined regulated by means of the spring 6. When the pression in the cylinder decreases, the

moment, which can be exactly needle-valve is closed and the diierential An automatic fuel supply pump and injection deviceforv internal combustion engines comprislng a bod having 'axially aligned and communlcatmg bores leading 'active to move said plston 'outwar from opposite ends thereof and providedpn' one side with a projection by meansof which the bod may be attached to an engine cylinder a differential piston arrange in one of said bores of the body, a duct extending through said projection and said body 'to the outer'side of the greatest diameter of said piston, so that said piston is in constant communication with the combustion space of the cylinder through said duct a spliun y, e supply duct leadin to the bore of the differential piston an having fuel supply regulating means, a needle valve in the other bore and having its outer end arra at the end of said body opposite that in which the greatest diameter of the differential pisis arranged, a

t 131cm tarily hold the needle valve in closed tion, and a duct leading from the bore in which the needle valve operates'through said projection, so that both the duct which'pute the combustion space of the c linder in comv munication with the outer si e of the largest diameter of the piston and the duct through both arranged in the sameprojection and the outer ends of the dierential piston and needle valve are accessibly located at opposite ends of the body.

Intestimonvwhereof, I have signed my name tothis specification.

nourmco Luis mannluxus umani.

ring active to moxvnen-l 'Y posir lwhich fuelv is supplied to the cylinder are 

